To the outside world, actress Zoe Saldana, 38, has it all. She's a successful actress, who's starred in blockbusters like "Avatar" and "Star Trek," and is happily married to Marco Perego — the couple welcomed twin boys to the world in 2014.
What you can't see from the glossy magazine photos: The star, along with her mom and sisters, recently revealed to Net-A-Porter that she suffers from an autoimmune disease, Hashimoto's thyroiditis.
Hasimoto's disease is a condition that causes the immune system to attack your thyroid, which is a small gland located at the base of your neck. Hashimoto refers to the Japanese surgeon who first described the disease in 1912.
"Your body doesn't have the energy it needs to filter toxins, causing it to believe that it has an infection, so it's always inflamed... You create antibodies that attack your glands so you have to eat clean," Saldana explained the condition in the online magazine.
This disease results in decreased levels of thyroid hormone, which is a hormone the body uses to regulate heart rate, temperature, digestion, metabolism, weight and many other processes, according to Dr. Sean McGann, an emergency physician and spokesman for the American College of Emergency Physicians.
Saldana opened up about how the disease hit her unexpectedly.
"...Then your doctor says you're losing calcium in your bones. What the f*** is that?!" said Saldana. "I would hear those conversations with my mom and grandma, thinking I'd never get there. I'm going to live forever! But all of a sudden it hits you," she told Net-A-Porter.
"Thyroid hormone plays a role in almost every body system," explained McGann. "So the decrease in thyroid hormone can cause symptoms such as fatigue, weight gain, dry skin, hair loss/thinning, constipation, depression, weakness, slow heart rate and sensitivity to cold."
It's commonly thought of as a genetic disease, but McGann pointed out there is research stating that environmental factors like radiation exposure could also contribute.
To combat the effects of this autoimmune disease, Saldana said she and her husband stick to a gluten- and dairy-free diet.
"The standard treatment is lifelong thyroid hormone replacement, which can usually be done with a daily oral medication," explained McGann. "Though optimal nutrition is important to help the body fight all disease processes."